In processes in which a processing target substrate is processed in a vacuum chamber, an electrostatic chuck is used as a means to fixedly hold the processing target substrate. In the electrostatic chuck, a voltage is applied to an electrode provided within the electrostatic chuck and a processing target substrate is adhered to a major surface of the electrostatic chuck by an electrostatic force. As the processing progresses, it may be necessary for the electrostatic chuck, as part of a given process, to perform actions such as rapidly heating and cooling the processing target substrate.
To meet this requirement, a Coulomb-type electrostatic chuck with low leakage between electrodes and favorable responsiveness of attachment and detachment for the processing target substrate over a wide temperature range is used. Besides the Coulomb-type electrostatic chuck, there also exists a Johnsen-Rahbek-type electrostatic chuck. However, in the Johnsen-Rahbek-type electrostatic chuck, the responsiveness of attachment and detachment of the processing target substrate and the leakage between electrodes are strongly dependent on temperature, and so this type may fail to meet the above-described requirements.
Note, however, that the electrostatic adhesion force offered by the Coulomb-type electrostatic chuck is weak relative to the electrostatic adhesion force offered by the Johnsen-Rahbek-type electrostatic chuck. Hence, in the Coulomb-type electrostatic chuck, to generate a strong electrostatic adhesion force the electrostatic chuck is required to be thin, and the voltage applied to the electrode is required to be high. As a consequence, it is necessary to improve insulation properties of Coulomb-type electrostatic chucks.
Examples of means to rapidly heat and cool the processing target substrate include a means whereby heat transfer gas is supplied between an electrostatic chuck major surface and the processing target substrate, and a means whereby a temperature control plate is added to the electrostatic chuck. For example, an electrostatic chuck with multiple protrusions, radially-extending grooves and a peripheral groove provided in the electrostatic chuck major surface has been proposed (see, for example, Patent Literature 1). In the electrostatic chuck, a comb-like electrode is provided under the electrostatic chuck major surface. Grooves for supplying the heat transfer gas are disposed so as to overlap the electrode. Further, a through hole is provided at a center of the electrostatic chuck, and the through hole communicates with radially-extending grooves. The radially-extending grooves communicate with a peripheral groove. Further, as a means to improve the insulation properties between the electrodes, a structure has been disclosed in which grooves are provided between the electrodes (see, for example, Patent Literature 2).